1. Field of Invention
The invention relates to redundant call processing. In particular, the invention relates to a method and apparatus for copying call information expeditiously and in a way that allows in-progress call processing to continue if an active call processor fails.
2. Description of Related Art
To assure reliability, redundancy is often built into telecommunications networks. Most network equipment, including call processors and databases, are duplicated to provide greater reliability in the event of equipment failure. For example, active call processors are backed-up by duplicate equipment, referred to as a standby call processor. Call processors are used during the call set-up stage (i.e., the time from call initiation to establishing the call connection) to process information, transmit instructions regarding routing, allocate network resources, approve the call and the billing, and gather further information where needed. If the active call processor fails, the standby call processor can take over to process new incoming calls.
To perform properly, the standby call processor must have the same information that is available to the active call processor. Thus, the standby call processor is periodically updated and the data synchronized with that of the active call processor. Generally, wherever network data is duplicated, it is periodically updated and synchronized. However, periodic updating is a problem when failure occurs between the updates. Thus, new technology is needed to reduce the effects of the failures between the updates.